Infections caused by the filamentous fungus Aspergillus fumigatus are a significant clinical issue and represent the second most-common form of fungal infection. Azole drugs are effective against this pathogen but resistant isolates are being found more frequently. Infections associated with azole resistant A. fumigatus have a significantly increased mortality making understanding drug resistan...

High-level azole resistance in the Darlington strain of Candida albicans was investigated by gene replacement in C. albicans and expression in Saccharomyces cerevisiae. We sequenced the ERG11 gene, which encodes the sterol C(14)alpha-demethylase, from our copy of the Darlington strain. Both alleles contained the histidine for tyrosine substitution at position 132 (Y132H) reported in Darlington ...

OBJECTIVES Recent increases in triazole resistance in Aspergillus fumigatus have been attributed primarily to target site (cyp51A) mutations. A recent survey of resistant isolates in Manchester showed that >50% of resistant isolates had no mutation in cyp51A or its promoter. We investigated the mechanisms of resistance in clinical azole-resistant isolates without cyp51A mutations. METHODS Twe...

OBJECTIVES To explore the mechanisms underlying azole resistance in clinical isolates of Candida tropicalis collected in China by focusing on their efflux pumps, respiratory status and azole antifungal target enzyme. METHODS Fifty-two clinical isolates of C. tropicalis were collected from five hospitals in four provinces of China and antifungal susceptibility tests were performed. Rhodamine 6...

Azole fungicides play a prominent role for reliable plant disease management. However, quantitative azole resistance has been shown to develop in fungal pathogens, including Fusarium graminearum, the causal agent of Fusarium head blight (FHB). Due to widespread application of azole fungicides, resistance may accumulate to higher degrees in fungal field populations over time. Although azole fung...

Invasive aspergillosis is a life-threatening mycosis caused by the pathogenic fungus Aspergillus. The predominant causal species is Aspergillus fumigatus, and azole drugs are the treatment of choice. Azole drugs approved for clinical use include itraconazole, voriconazole, posaconazole, and the recently added isavuconazole. However, epidemiological research has indicated that the prevalence of ...

Candida albicans azole-resistant clinical isolates overexpressing the CDR1 and CDR2 genes (multidrug transporters) also overexpress the PDR16 gene (phosphatidylinositol transfer protein). We show here that the PDR16 promoter displays higher transcriptional activity following integration in an azole-resistant isolate than in the matched azole-susceptible one. Thus, the upregulation of PDR16 in t...

Azole resistance is an emerging problem in Aspergillus which impacts the management of aspergillosis. Here in we report the emergence and clonal spread of resistance to triazoles in environmental Aspergillus fumigatus isolates in India. A total of 44 (7%) A. fumigatus isolates from 24 environmental samples were found to be triazole resistant. The isolation rate of resistant A. fumigatus was hig...